On the determination of fault plane solutions of weak crustal earthquakes of Vrancea region (Romania)

An inversion scheme using only few good quality high-frequency local waveforms was previously applied to estimate the source mechanism for a pilot set of crustal earthquakes with local magnitudes less than 4, from the bend of the South-eastern Carpathians. Taking advantage of the improved velocity and attenuation models recently determined for the study region, we reevaluate the focal mechanism of a couple of low-magnitude events (local magnitude ≥ 3), and assess the uncertainty of the fault plane solutions. The results evidence the increased reliability of the retrieved mechanisms and emphasize the capability of the approach to provide satisfactorily constrained fault plane solutions for the weak-to-moderate earthquakes in the study region.